1 /*
2 * Silicon Graphics RLE 8-bit video decoder
3 * Copyright (c) 2012 Peter Ross
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 /**
23 * @file
24 * Silicon Graphics RLE 8-bit video decoder
25 * @note Data is packed in rbg323 with rle, contained in mv or mov.
26 * The algorithm and pixfmt are subtly different from SGI images.
27 */
28
29 #include "libavutil/common.h"
30
31 #include "avcodec.h"
32 #include "internal.h"
33
sgirle_decode_init(AVCodecContext * avctx)34 static av_cold int sgirle_decode_init(AVCodecContext *avctx)
35 {
36 avctx->pix_fmt = AV_PIX_FMT_BGR8;
37 return 0;
38 }
39
40 /**
41 * Convert SGI RBG323 pixel into AV_PIX_FMT_BGR8
42 * SGI RGB data is packed as 8bpp, (msb)3R 2B 3G(lsb)
43 */
44 #define RBG323_TO_BGR8(x) ((((x) << 3) & 0xC0) | \
45 (((x) << 3) & 0x38) | \
46 (((x) >> 5) & 7))
47 static av_always_inline
rbg323_to_bgr8(uint8_t * dst,const uint8_t * src,int size)48 void rbg323_to_bgr8(uint8_t *dst, const uint8_t *src, int size)
49 {
50 int i;
51 for (i = 0; i < size; i++)
52 dst[i] = RBG323_TO_BGR8(src[i]);
53 }
54
55 /**
56 * @param[out] dst Destination buffer
57 * @param[in] src Source buffer
58 * @param src_size Source buffer size (bytes)
59 * @param width Width of destination buffer (pixels)
60 * @param height Height of destination buffer (pixels)
61 * @param linesize Line size of destination buffer (bytes)
62 *
63 * @return <0 on error
64 */
decode_sgirle8(AVCodecContext * avctx,uint8_t * dst,const uint8_t * src,int src_size,int width,int height,ptrdiff_t linesize)65 static int decode_sgirle8(AVCodecContext *avctx, uint8_t *dst,
66 const uint8_t *src, int src_size,
67 int width, int height, ptrdiff_t linesize)
68 {
69 const uint8_t *src_end = src + src_size;
70 int x = 0, y = 0;
71
72 #define INC_XY(n) \
73 x += n; \
74 if (x >= width) { \
75 y++; \
76 if (y >= height) \
77 return 0; \
78 x = 0; \
79 }
80
81 while (src_end - src >= 2) {
82 uint8_t v = *src++;
83 if (v > 0 && v < 0xC0) {
84 do {
85 int length = FFMIN(v, width - x);
86 if (length <= 0)
87 break;
88 memset(dst + y * linesize + x, RBG323_TO_BGR8(*src), length);
89 INC_XY(length);
90 v -= length;
91 } while (v > 0);
92 src++;
93 } else if (v >= 0xC1) {
94 v -= 0xC0;
95 do {
96 int length = FFMIN3(v, width - x, src_end - src);
97 if (src_end - src < length || length <= 0)
98 break;
99 rbg323_to_bgr8(dst + y * linesize + x, src, length);
100 INC_XY(length);
101 src += length;
102 v -= length;
103 } while (v > 0);
104 } else {
105 avpriv_request_sample(avctx, "opcode %d", v);
106 return AVERROR_PATCHWELCOME;
107 }
108 }
109 return 0;
110 }
111
sgirle_decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)112 static int sgirle_decode_frame(AVCodecContext *avctx, void *data,
113 int *got_frame, AVPacket *avpkt)
114 {
115 AVFrame *frame = data;
116 int ret;
117
118 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
119 return ret;
120
121 ret = decode_sgirle8(avctx, frame->data[0], avpkt->data, avpkt->size,
122 avctx->width, avctx->height, frame->linesize[0]);
123 if (ret < 0)
124 return ret;
125
126 frame->pict_type = AV_PICTURE_TYPE_I;
127 frame->key_frame = 1;
128
129 *got_frame = 1;
130
131 return avpkt->size;
132 }
133
134 AVCodec ff_sgirle_decoder = {
135 .name = "sgirle",
136 .long_name = NULL_IF_CONFIG_SMALL("Silicon Graphics RLE 8-bit video"),
137 .type = AVMEDIA_TYPE_VIDEO,
138 .id = AV_CODEC_ID_SGIRLE,
139 .init = sgirle_decode_init,
140 .decode = sgirle_decode_frame,
141 .capabilities = AV_CODEC_CAP_DR1,
142 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
143 };
144